如何产生的，从两个列表嵌套列表在python

Question

我Python中的新手， 我有两个列表：

l1 = ['a','b','c','d'] 
l2 = ['new'] 

我想这样

l3 = [('a','new'),('b','new'),('c','new'),('d','new')] 

新的名单是什么结合这两个列表的最好方法是什么？

Answer 1

>>> from itertools import product 
>>> l1 = ['a','b','c','d'] 
>>> l2 = ['new'] 
>>> list(product(l1,l2)) 
[('a', 'new'), ('b', 'new'), ('c', 'new'), ('d', 'new')] 

Answer 2

>>> from itertools import repeat 
>>> l1 = ['a','b','c','d'] 
>>> l2 = ['new'] 
>>> zip(l1,repeat(*l2)) 
[('a', 'new'), ('b', 'new'), ('c', 'new'), ('d', 'new')] 

Answer 3

见itertools docs。

特别是，使用产品的笛卡尔乘积：

from itertools import product: 
l1 = ['a','b','c','d'] 
l2 = ['new'] 
# Cast to list for l3 to be a list since product returns a generator 
l3 = list(product(l1, l2)) 

Answer 4

如果l2永远只是有一个元素，没有必要过分复杂化的东西

l3 = [(x, l2[0]) for x in l1] 

Answer 5

你可以简单地使用列表没有任何功能的理解：

l3 = [（x，y）for x in l1 for y in l2]